Relay construction



June 2, 1970 w. A. DEPNER 3,516,039

RELAY CONSTRUCTION Filed Aug. 21, 1968 INVENTOR. W! LLIAM A DEPNER ATTY.

United States Patent Oflice 3,516,039 Patented June 2, 19 70 US. Cl.335-270 2 Claims ABSTRACT OF THE DISCLOSURE The bearing pin on which thearmature of a relay is pivotally mounted to the relay heel piece issecured in apertures in upturned ears of the aramture by de forming thesoft armature material around and above the apertures sufficiently tocause the bearing pin and the apertures to assume an out of round shape.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates generally to relays and more particularly to a method ofsecuring the armature bearing pin on relays or rotary switches.

Electromagnetic relays of the type having a bearing pin secured to thearmature are extensively used in telephone systems and have proven quitesatisfactory. During the many operations of a relay the armature issubjected to a pounding action when it strikes the relay core and thisrepeated operation may gradually loosen the bearing pin in the armature.As the bearing pin becomes loose the mechanical and electricalcharacteristics of the relay are altered to such an extent that therelay can no longer be adjusted to perform the function it was designedto accomplish.

Prior art A variety of methods of securing the bearing pin to a relayarmture, including the following, have heretofore been used:

(1) Knurl one end of bearing pin and force fit into armature hole andflare other end.

(2) Insert bearing pin having no knurling, but having coaxial holesdrilled in both ends, into armature holes and flare both ends againstouter armature surface.

(3) Insert pin having holes in both ends into armature and stake usinground or square stake to expand armature bearing pin outward againstmagnetic iron material.

The above methods attempt to secure a stainless steel or Phosphor bronzebearing pin to the annealed magnetic iron armature by a flaring and/orstaking operation which expands a hard resilient, memory retaining, highspring back characteristic type material against a relatively dead softannealed magnetic iron material having a poor memory, or practically nospring back characteristic. Consequently, after the flaring or stakingoperation, the resilient bearing pin tends to spring back to itsoriginal shape. The soft armature material, on the other hand, takes aset to the maximum expansion caused.

by the flaring or staking operation. These two diametrically opposedactions of the mating parts allows a relaxation of the tightness betweenthe surface engagement of the bearing pin and the armature material,resulting in loose armature bearing pins.

It is a general object of this invention to increase the reliability andto reduce the cost of maintenance of relays.

Another object of the invention is to provide an improved technique forsecuring the bearing pin to a relay armature.

SUMMARY OF THE INVENTION The present invention provides a means tosecure the armature bearing pin to the armature to prevent the bearingpin from rotating. The bearing pin, with coaxial holes drilled in eachend, is inserted into openings in the upstanding ears of the armature.Pressure applied to the periphery of the ears in a direction normal tothe axis of the bearing pin, sufficient to distort the roundness of thehole in the armature ear and the end of the bearing pin, prevents thebearing pin from rotating.

DESCRIPTION OF THE DRAWING The nature. of the invention and itsdistinguishing features and advantages will be more clearly understoodfrom the following detailed description, taken in conjunction with theaccompanying drawing, wherein:

FIG. 1 is a top or plan view of a relay;

FIG. 2 is a side view of the relay shown in FIG. 1;

FIG. 3 is a perspective view of the armature assemy;

FIG. 4 is an enlarged side view of an ear of the armature showing thedeformed end of the armature bearing pin; and

FIG. 5 is a cross-sectional view taken along the line 5-5 of FIG. 4.

DETAILED DESCRIPTION Referring now to the drawings, and moreparticularly to FIGS. 1 and 2, there is shown an electromagnetic relay10 having the usual field structure comprising a core 25, a winding andan L-shaped heel piece 23 secured to the core by means of a screw 24. Anarmature 12 is pivotally secured to the heel piece by a bearing pin 16,a yoke 13, a clamp washer 14 and a screw 15. The yoke has bearing pointsat 21 and 22 for the bearing pin 16.

As better seen in the perspective view of FIG. 3, the bearing pin 16 isrigidly secured in holes or openings in the upturned ears 17 and 18 ofthe armature 12. The bearing pin 16 has a hole 20 drilled in each endthereof to a depth of approximately the thickness of the ear. As inconventional relays, armature 12 is formed of soft magnetic iron, whichhas a low elastic limit. The bearing pin 16, on the other hand, isformed of a hard material, such as Phosphor bronze, which has a muchhigher elastic limit.

' In accordance with the invention, the pin 16 is secured to thearmature by deforming the material of the ears 17 and 18 from the shapeindicated by the dotted lines in FIGS. 4 and 5 to the shape shown by thesolid lines 19. This may be accomplished by clamping the armatureassembly in a suitable jig and applying sufficient pressure to the earsat a point generally above the pin to collapse the material of the earsin the region above and around the pin, and the pin itself. The presenceof the coaxial holes 20 in the ends of the pin 16 cases the deformationof the pin into a shape other than round-generally oval, as shown.

Unlike the prior art systems in which the differing elastic propertiesof the armature and pin compete in a way tending to loosen the pin, inthe instant case the soft magnetic iron set in its deformed conditionand the relatively more elastic Phosphor bronze pin, which tends torestore to its original shape, maintains rigid contact with the materialof the upstanding ears. That is, the different elastic propertiescooperate to maintain secure contact between the pin and armature. Theout-of-round shape of the pin, and the continuously applied forceagainst the surfaces and rotation of the pin relative to the armature.

While the invention has been described as applied to a relay, it will berecognized that it has utility in any situation where it is desired tosecure a pin of high elasticity to a member of relatively lowerelasticity.

What is claimed is:

1. In a switching device; an armature of a magnetic material having asubstantially low elasticity; an ear formed on said armature; a bearingpin of a material having a substantially high elasticity; an opening insaid ear and having one end of said bearing pin inserted therein; acoaxial opening in said one end of said bearing pin, and extendingtherein to a depth approximating the thickness of said ear; said coaxialopening enabling the simultaneously deforming of said opening in saidear, said one material having a substantially low elasticity; an ear"formed on each side edge of said armature, and extending at right anglesto the plane'of said armature; a bearing pin of a material having asubstantially high elasticity; an

4 opening in each said ear; each said ear opening engaged by an end ofsaid bearing pin; a coaxial opening formed in each end of said bearingpin, and extending therein to a depth approximating the thickness ofeach said associated ear; said coaxial openings enabling thesimultaneous deforming of said openings in said ears, said ends of saidbearing pin and the coaxial openings, in response to the'deforming of aportion of the periphery of each said ear in a direction normal to theaxis of said bearing pin, for permanently engaging each said end of saidhearing pin with the associated said ear; each said bearing pin endthereafter maintained in said permanent engagement with said associatedear in response to the differences in saidelasticity of said armatureandsaid bearing pin materials.

References Cited UNITED STATES PATENTS 1,449,677 3/1923 Jones 287-203 X3,092,702 6/1963 Parsons 335-128 X BERNARD A. GILHEANY, Primary ExaminerR. N. ENVALL, Jr., Assistant Examiner 1 US. Cl. X.R. zap-20.3,

